tree e2fe5ddb7ae33d7b764c1eb89ada5b959671da91
parent 0bc1407ba80ac63409433a82139ed20139c79c3e
author Jiyong Park <jiyong@google.com> 1687149686 +0900
committer Jiyong Park <jiyong@google.com> 1687568147 +0900

ro.log.file_logger.path works even via libbase

Previously, even if ro.log.file_logger.path is set, logs written via
libbase APIs were not written to the file. This was because the sysprop
was ignored if a custom logger is set and libbase registers a custom
logger (LogdLogger).

This behavior was very confusing because it meant that depending on
which logging API you use, you get different results; `ALOGI("msg");`
goes to the file, whereas `LOG(INFO) << "msg";` goes to logd, or
silently ignored in a logd-less environment like Microdroid.

This change fixes the issue as follows:

* The sysprop doesn't change the global logger function. This was the
  original behavior before the introduction of the sysprop.

* Instead, `__android_log_logd_logger` checks if the sysprop is set, and
  if so writes the log to the file. If the sysprop is not set, the log
  goes to logd as before.

* The check for sysprop and file descriptor for the file are cached as
  before.

Bug: 270566364
Test: vm/vm_shell.sh start-microdroid  -- --protected --console \
/data/local/tmp/console.txt --log /data/local/tmp/log.txt

Check that all logs (except for those from init and kernel) are in
log.txt.

Change-Id: I06ea1a6ee3732eb9eafe7794b9dfdcc34f5c1f83